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, of the pieces to be rotated by the lathe.

lutnl @Stairs man @Ww CHARLES V. W'OERD, OF WAL'lHAh/I, ASSIGNOR TOAMERICAN -WA'ICH COMPANY, OF BOSTON, MASSACHUSETTS.

Leners Patat No. 90,620, dated May 25, 1869.

` LATI-IE FOR GRINDING AND POLISHING PIVOTS OF WATCH-WORK.

The Schedule referred to in these Letters Patent and making part of thelame.

To all whom it may concern:

, Be it known that I, CHARLES Y. XVoEnD, of Waltham, in the county ofMiddlesex, and State of Massachusetts, have invented Improvements inLathes for Grinding and Polishing Pivots, Staffs, and other Watch-formand I do hereby declare that the following, taken in connection with thedrawings, which accompany and form part o' this specification, is adescription of my invention, sufficient to enable those skilled in theart Vto practise it.

The machine upon which my improvements are based, is essentially alathe, adapted either to chucking-work, or to mounting it upon centres,provided with a rotating polishing-wheel, to be lsupplied with neabrasive powder, said wheel boing so arranged, "that by changes in itsposition, it can be brought to operate upon the rotating body, to beground to any required size, or to be polished, and can also be broughtagainst revolving laps or grinders, by which its actingsurfaces andangles are kept perfectly true, so as to produce correct results ingrinding and polishing.

Figure l, of the drawings, represents, in front elevation, a machineembodying my invention,

Figure 2 showing the same in plan.

On a common bed-piece, u, are arranged stands, b c d, the stand bsustaining a lathe-bed, c, the stands c and d, respectively, supportingbearings, in which rotate the arbors ot" the grinding lap-wheels f andy.

The lathe-bed isprovided with a head-stock, it, having a rotating arbor,i, turned bya belt operating on the pulley j, one end of the arbor beingadapted to receive centres or chucks, according to the requirements Thisheadstock is of peculiar construction, constituting one part of myinvention.

In lugs 7.', integral with or fixed to the head-stock 7i., are formedbearings, to receive the shaft Z, the axis of which is parallel with theaxis ofthe arbor i.

On one end oi'shaft l is fixed an arm, m, as shown,

which bears the still or dead-centre of the lathe, the other end ofshaft l having iixed thereon an arm, n, which fits upon a guide-pin, o,secured in the head- Stock parallel with the axis ot' its arbor i, sothat by sliding the shaft l in its bearings, the Vstill cent-re can bebrought near to or can he removed from the revolving centre placed inthe end of the arbor, and thus pieces of any length, adapted to thestructure of the lathe, can be pivoted on the lathe-centres, thesetscrew p', operating on shaft i', serving to lix and hold the centresat the requisite distance apart.

For chucking-work, I remove the head-stock l1, and replace it withanother head-stock, similar, except that it is provided, at the end ofarbor i', with the usual provisions for receiving chucks, and is withoutthe dead-centre bearing-attachment.

This construction and arrangement is lighter, more compact, cheaper, andmore accurate than is the comtail-stock piece, which is now used, and itenables me to make rise ofthe space on the lathe-bed, usually 0ccupiedby a tail-stock, for the attachment of the stand p, on which myrotating, polishing, or grinding-wheel q'is mounted.

A swinging frame, r, is pivoted at one end to the stand l), the arbor s,ofthe polishing-wheel q, being mounted in bearings formed in the otherend of the frame' r, there being on the arbor. a belt-pulley, t, bywhich rapid rotation is given the polisher q.

This polisher is made as the frnstum of a cone, and of soft steel, andits operating-times are ground perfectly true by being brought intocontact, as often as may be required, with-the rotating grinding-wheels,or laps fand g.

Those who are acquainted with the extreme minuteness of. many of thepivots of a train of watch-gearing, will appreciate the absolutenecessity for mathematical exactnoss in form and movement ofpolishingwhcels which are brought to bear upon them, to imthem the highdegree of smoothness and finish needed to make them run properly in finewatch-movements.

The wheel q is fixed to its arbor, and, being ground thereon, willrotate with exactness so long as thearbor fits in its bearings. It isnot found practical to remove the wheel from its arbor, or the arborfrom its bearing, to grind the wheel,- and then to replace it on them,and then have the wheel rotate with the exactness requisite.

Besides, it is necessary frequently to retoueh or regrind thepolishing-wheel q, so as to preserve the accuracy and sharpness of theangle made at the juncor worn very quickly in its use.

The drawings show, with accuracy and clearness, the manner oi mountingand rotating the grindinglaps, so that it is unnecessary to burden thisspecification with a description of so simple a mechanism.

, The laps themselves may be made Vof any suitable abrasive material, orcompound.

Their form is that ofshort cylinders, a'ixed to heads or disks, by whichthey are secured on their arbors, the operative-faces of the laps vbeingthe ring-ends oi the cylinders, which revolve in planes.

The lap gcan be adjusted by eudwise-movement of its shaft, so as to comeinto contact with and grind the cylindrical surface of the plisher q, asit Wears away.

I The lap f, which grinds the face of the polisher to aA plane, may havea similar provision, though not ab soltely necessary, as the arbor ofthe-polishing-Wheel mon arrangement of the dead-centre in a separate"part to them the exact sizes required, and to give to tion of its twooperative-faces, as the angle gets dulled in the lathe, to be ground andpolished thereby.

When sta's, and other parts of watches, or similar small Work, requirevto be ground, orfpolishcd on a taper, then the periphery of the wheel qmust be ground to correspond to the taper to be produced. This iseffected by so arranging the head which has the bearings'for the arborof the lap g, that theaxis of said arbor may be set to' any desiredangle with reference to the arbor s of lthe polishing-wheel. To effectthis, the top of the support d is extended into a large plane surface,a, to which the head t', which forms the bearings for the arbol1` of thelap y, is pivoted at a point under the grinding-face of the'lap, and ina vertical plane passing through the axis of said arbor. `YVhen the heade is moved upon its pivot to the place requisite to give the properangle or taper to the periphery of the Wheel q, it is clamped orfastened by any suitable means.

To grind to a given size the diameters of any chueked work, netreqniring the use of the still, or` dead, or back-centre, I make use of.the following device: p

I place in a post, w, Whichmay be secured in position as shown in thedrawings, a flat-surfaced diamond, or other material, of the requisitehardness, and adjust its height above the axial line of the arbor i,

to the radins of the size to which it is required toiinish the workrotating with the lathe.

The position of the diamond, which is denoted by a1, is such as to comebeyond the end of the piece to be ground, but in the path of theperipheral grinding-face of the wheel q;

`It will be seen that the wheel will grind until its eral grinding-faceon the dia-mondiy Thus, pivots, or other small, short cylinders may beground and polished in numbers to the same diameters. y

I'claim, in combination with the head-stock of a lathe, a shaft, orslide, l, provided with a back-centre bearing-piece, fm, and a guide.,il, or its equivalent, substantiallyas described. y

Also, the combination, with a lathe, of a-swinging frame, or bearing,'apolishing-wheel, and a grindinglap or laps, arranged to operatesubstantially" as described. .y

Also, the combination, with apolishing-wheel, of a gauging-stop,arranged to operate substantially as described. v

' CHAS. V. VOERD.

Witnessesz J. B. Gaosr, I FRANCIS GOULD.

swinging movement is stopped by abuttal ot its perph-

